The purpose of this booster study is to evaluate the immune persistence in healthy Chinese subjects primed in study NCT01086423 with GSK Biologicals' Infanrix-IPV+Hib™ (DTPa-IPV/Hib) vaccine. The study will also evaluate the safety and immune response of these subjects to a booster dose of Infanrix-Hib™ (DTPa/Hib) and Poliorix™ (IPV) vaccine.